Arizona's interdistrict open enrollment and charter schools laws allow families to send their children to the public schools of their choice. We assessed how public school choice affected elementary school enrollments in 27 metropolitan Phoenix school districts. Student mobility rates varied widely between districts and by location. The higher mobility rates of small urban districts were driven by the movement of students to and from other districts within the metropolitan area. Larger suburban districts had higher rates of district-to-charter school movement and charter school-to-district movement. Neither form of public school choice changed existing patterns of between-district racial stratification. (Contains 1 figure, 3 tables, and 10 notes.)